问带通配符的番石榴Maps.difference

EN

Maps.difference(left, right, new Equivalence<String>() {
  @Override public boolean doEquivalent(String a, String b) {
    return "*".equals(a) || "*".equals(b) || Objects.equals(a, b);
  }

  // You have to hash all strings to the same thing because you
  // don't know if the current item is a "*", or its corresponding
  // item is a "*". But actually it doesn't matter, because I don't
  // think it's invoked in difference.
  @Override public int doHash(String s) { return 0; }
});